One common possibility to fix a cable to an electrical unit is to solder a connector having a table like shape to the electrical unit. Thereby, the connector is electrically conducting and has an essentially flat surface located in some distance to the electrical unit. Usually such connectors have a hole in the flat surface whereby the hole can optionally have a thread. A cable which is to be fixed to the electrical unit is usually connected to a ring-terminal or a similar type of cable terminal. In order to fix the cable terminal to the connector, the cable terminal can be placed onto the flat surface of the connector and fixed with a screw, either by using the thread in the hole or a nut placed on the opposite side of the flat surface above the electrical unit. Thereby, the ring or equivalent part of the cable terminal is squeezed between the head of the screw and the flat surface of the connector and thus, an electrical connection is established via the cable, the cable terminal, the connector and the electrical unit.
A disadvantage of this system is that it has a certain height. Connectors, rising up above the electrical unit surface and being soldered to it, can be ripped off while mounting or dismounting other elements on the electrical unit. Finally, as cables are in general mounted after placing an electrical unit in its final position, e.g. in a casing, the cables have to be mounted on the top side of the electrical unit. This creates easily a mess and in many cases the cables are an obstacle, if there is work to do on the electrical unit.
There exists further a method of screwing a ring-terminal directly to an electrical unit. While this method avoids the table-shaped connectors, it has the problem that access to the backside of the electrical unit is needed in order to place and hold a nut with the required thread for the screw. This access is often difficult or even impossible to obtain.
Another connection system is presented in US 2013/0303033 (Alltop Electronics). This document discloses a power connector. The system comprises an insulating housing with a plurality of passageways. Power contacts with a U-shape and a width similar to the passageways are inserted and fixed by a screw which passes from a rear cavity of the opposite side of the housing through a small opening into a hole with a thread in the power contacts. There is a terminal module in the rear cavity where cables can be fixed to. In this way, an electrical connection can be established between the cables fixed to the rear cavity and the cables connected to the U-shaped power contacts.
However, this document describes a cable-to-cable connection system. It offers therefore no solution for the question how to connect a cable directly to an electrical unit without the need of an additional cable.
Thus, there is a need to develop alternative and improved methods and systems which overcome the aforementioned drawbacks. More specifically, there is a need for an system for connecting a cable to an electrical unit. Preferably, the system should be as compact as possible and allow for an easy installation and connection of the cable to the electrical unit. Additionally, the system should especially facilitate connecting a cable to an electrical unit in a casing. Preferably, the system also enables a neater wiring.